Impact of γ-irradiation on physicochemical properties of freeze dried Amorphophallus paeoniifolius flour.

Freeze dried raw (FDR) and freeze dried blanched (FDB) Amorphophallus paeoniifolius flours were irradiated at doses of 3, 6 and 12kGy. The irradiated flours were investigated for physicochemical, pasting, textural, thermal and morphological properties. Reduction in amylose content was observed with increasing irradiation dose. Carboxyl content of the flours increased significantly at higher doses. Decline in lightness (L(∗)) and increase in redness (a(∗)) were found to increase with the elevation of dosage. Irradiation caused reduction in the values of pasting parameters of freeze dried raw as well as freeze dried blanched samples. Hardness of the flour gels exhibited increase at all the doses except at 3kGy. Decrease in onset gelatinization temperature of both FDR and FDB flours was observed with increasing irradiation dose. FDR as well as FDB flours exhibited increasing trend in their enthalpy (ΔHgel) values following irradiation treatment. Raman spectroscopy revealed that no new functional groups were introduced by irradiation treatment. However, band intensity of functional groups in irradiated FDR flours was reduced with increment of dose.